The invention pertains to a lock. At least one longitudinally movable locking bar is provided, which moves in a direction determined by a longitudinal guide. The locking bar is driven by an actuator, which operates by way of a rotor. The outer end of the bar engages in a locking opening in the stationary part of the lock.
In the known lock of this type (WO 95/27115 A1), the two locking bars and the rotor are made as a single piece of plastic, but elastic tabs are used to connect the rotor to the bars. In the assembled lock, these tabs are intended to exert elastic force on the locking bars to keep them in their locking position. This is achieved by producing the two locking bars, the two tabs, and the rotor located between the bars in a stretched-out state and by bringing the tabs into a bent position upon installation in the door, as a result of which they act as leaf springs. A manipulator, which presses against a transverse wall molded onto one of the locking bars and which pivots the rotor by way of the associated tab out of the locking position, is used as an actuator for moving the locking bar. To increase the flexibility of the tabs at the points where they are connected to the rotor, the tabs are made very thin. This negatively affects the strength of the lock; the tabs can break easily at these sensitive connecting points. If this happens, the known lock becomes unusable. The longitudinal guides for the two locking bars consist of strips a certain distance apart, which enclose between them a cross section of the locking bar. No guides are provided in the area of the elastic tabs or in the area of the rotor.
In a lock of a different type (DE 44 00 628 A1), so-called “film hinges” are provided between rigid sections of the locking bars, two rotors, and the connecting bars; these hinges produce a flexible connection between these parts, which are rigid in and of themselves. Film hinges of this type are susceptible to breakage. If a film hinge breaks, the lock is unusable.
In a lock with three bars (DE 23 19 315 A), the two locking bars which move in opposite direction are attached to the bearing ends of two connecting rods, which are connected by elastic bands to a rotor, which can be turned by a key. The rotor, the two elastic bands, and the connecting rods are produced as a single unit out of plastic. When the rotor is turned, the connecting rods can execute a limited pivoting movement inside the lock housing, whereas their bearing ends are guided longitudinally in grooves in the lock housing. The elastic bands extend along radial slots in the rotor and merge with the inner ends of the associated connecting rods. These transition points tend to break easily, however, because of their thinness and because of the load exerted on them during the pivoting movements. The connecting rods have a grooved profile adjacent to their ends, into which the rotor can fit when the connecting rods pivot to the maximum extent. In the minimum pivot position of the connecting rods, their ends are designed to be supported on flattened circumferential areas on the rotor, in which case the elastic bands are bent at a right angle. The locking bars in this case are components which are independent in any case of the gear assembly, and they must be produced separately and then connected in an articulated manner to the two bearing ends of the gear assembly. Play must be allowed between the connecting rods and the locking bars and between the bearing ends and the housing grooves, but this play causes noise when the vehicle is moving.